1. Field of the Invention
The present invention relates generally to the art of burning waste liquids such as solvents or light hydrocarbon fraction liquids in packaged burners and boilers. More particularly, the system relates to the simultaneous burning of such liquids with conventional fuel such as natural gas or fuel oil.
2. Description of Related Art
Numerous manufacturing processes produce flammable liquid wastes, many of which are classified as hazardous or toxic chemicals which require costly disposal. If such flammable liquids are disposed of by various waste disposal processes, the potential energy contained in the wastes is lost, compounding the expenses entailed in the disposal process.
It is an object of the present invention to provide a safe system for the combusion of volatile liquids and solvents in which the energy of the liquid waste is utilized as a boiler fuel.
One prior art method, attempting to utilize volatile solvents and liquids as a fuel, entailed mixing those materials in fuel oil. Such fuel mixtures, are often unsatisfactory in that the solvents contain materials which are highly corrosive to control valves and other components required for the operation of the system.
Another prior art approach involves feeding a constant but limited amount of solvent to the burner. However, since such systems are unmodulated, the ratio of solvent to fuel constantly changes. At periods of low firing rates, the proportion of solvent is at maximum percentage of the total fuel being fed to the boiler. Such a situation can lead to unsafe conditions in that the waste materials may contain non-uniform amounts of moisture or other non-flammable materials which may cause the boiler to burn poorly or even go out. If such an occurrence is followed by a slug of highly volatile materials, explosive conditions can result.
Another system heretofore employed by the present inventor entailed the use of two metering pumps for a boiler, one for the conventional fuel and another for the volatile solvent. A mechanical connection was employed to cause the two valves to open and close simultaneously so that a constant proportion of volatile solvents was present in the fuel mixture. A rate of air feed to the boiler in proportion to the total amount of fuel to provide air in excess of a stoichiometric combustion mixture. While such a system has operated satisfactorily, the types of boilers on which the same can be employed is limited by the physical arrangement of the boiler and furnace components. Due to such constraints it has been hithertofore impossible or impractical to employ such systems on many boilers. A need has thus continued to exist in the art for a system which can safely and efficiently utilize solvents and volatile liquids as a fuel, and which can be attached to most or all boiler systems.